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Wireless Takes Over

WiFi has become a primary (if imperfect) networking option for many academic institutions. But get ready: Recent advances are positioning WiFi to become your academic communications hub.

AFTER STARTING OFF as a simple way to provide
users with access to internet resources, WiFi networks have evolved
to become an important communications cornerstone for a growing
number of academic institutions. Not only have colleges been working
to make these networks available across their entire campuses
(or at least pretty close to 100 percent available), but wireless communications
also have begun to emerge as a primary mode of carrying
video and voice transmissions. As a result, WiFi network usage
is becoming as common as wired connections on some campuses.

While making dramatic inroads, the technology's evolution has
encountered a number of significant hurdles, a few of which vendors
still need to clear: First, in order for WiFi networks to span campuses,
their management functions need to be enhanced, a step that has
already taken place. Next, to carry video transmissions, their
throughput needs to be upgraded to higher speeds, something that is
still a work in progress. Finally, to support voice communications,
they need to be able to allocate bandwidth in a more granular manner,
another task still evolving. Bottom line? Though imperfect,
WiFi has become a primary networking option for
many academic institutions.

Emory University, in Atlanta, GA, is
a perfect example of the dramatic change
in the way academic institutions are
using WiFi networks. After determining
that students needed more wireless
options than the university was providing,
campus administrators and technologists
launched Emory Unplugged,
a massive project designed to overhaul
and expand the institution's wireless services,
so that they would be available
campuswide.

Because of its initial design, the wireless access point (AP) was
tough to deploy and manage, thwarting ubiquitous wireless
connections on campuses. Emory University needed five full-time
engineers to configure and manage its APs. But now just two
Emory technicians can monitor all of the institution's AP
connections from a central console.

"Incoming students are technology-savvy
and expect wireless connections
to be available wherever they roam on
campus," explains Stan Brooks, wireless
architect for Emory. The university,
which began expanding its network
footprint at the beginning of 2005, currently
has more than 1,000 access points
(APs) running across campus. Wireless
connections are now available in many
of Emory's academic buildings as well
as in its 55 residence halls.

As WiFi Expands,
Problems Emerge

Emory is not unique. At many other higher
ed institutions, dozens, hundreds, and
even thousands of APs are popping up.
Yet as the networks grow, many IT
departments have trouble keeping pace,
and there's a good reason for that. Traditional
methods of deploying wireless networks
focused on standalone, intelligent
APs. The devices were easy to install, and
the vendors' initial focus was to make the
systems' wireless signals stronger and the
systems' bandwidth more granular
through the development of more sophisticated
antennas that moved transmissions
from users' computers to campus
networks. But because the initial design
of the APs was centered on standalone
systems, making wireless connections
ubiquitous has been difficult. Many of the
older wireless networks featured "fat"
APs (running a lot of installation and
management software), which IT staffers
found difficult to deploy and manage.
Typically, each AP's security policies had
to be individually configured, so deploying
these connections was a manually
intensive undertaking. In the case of
Emory, the school needed five full-time
engineers to configure and manage its
APs. Not surprisingly, many other universities
quickly discovered that deploying,
upgrading, and managing these
distributed devices on a wide-scale
basis was complex, time-consuming,
and expensive.

Another limitation university technologists
uncovered: The networks were
not robust. APs often dropped connections
as users moved from one area (or
AP) to another location. One reason for
this is that APs with overlapping coverage
areas sometimes could not operate
on the same channel. To try and avoid
such problems, university technicians
completed site surveys (often performed
simply by walking around campus and
testing connections) to determine coverage
patterns. Then they re-stationed
their APs for minimal interference.

However, despite these steps, the
process sometimes resulted in coverage
gaps, and users were no happier. Many
mobile workers, for instance, had to reauthenticate
themselves with the network
as they moved out of one AP's coverage
area and into the next, and the available
bandwidth dropped as they came closer
to the boundary lines between coverage
areas. In response to the connection
problems, the IEEE devised the 802.11r fast-roaming standard
(which enables users to authenticate
themselves at one AP and have that information
move to a neighboring system),
and the 802.11k standard for radio
resource management (which speeds up
network handoffs between APs).

.

APs Go on a Diet

Another change vendors made was to
enhance their systems so that they could
be managed from a central location. They
moved away from fat APs to thin ones—
rather than producing
APs loaded with intelligence,
the suppliers
built devices that
relied less on the AP
and more on central
switches. Equipment
from Aruba Networks, for instance,
now allows Emory University to monitor
all of its connections from a central
console, and use a consistent set of management
tools. Consequently, instead of
the five full-time technicians, only two
network engineers are now needed to
configure and manage the school's
wireless network.

To prevent video transmissions from overrunning its network,
technologists at Washington University in St. Louis limit the
amount of data students can transmit via P2P applications—and
that includes bandwidth-hogging video. But the university will
double its 1,000 Meru Networks APs in the next 12 to 18 months.

Caught in the Switch

In the fall of 2004, to accommodate
6,000-plus undergraduate students and
the rest of the campus community, Villanova
University (PA) administrators
decided to expand the reach of the campus
wireless network. Behind the decision
was a change in the institution's
computer policy, requiring all freshmen
to have laptops. But as campus technologists
began to expand the school's
wireless LAN footprint, Villanova (like
Emory) found itself caught in the transition
vendors were making.

"We started out with some older WiFi
equipment, but with it we could not
deploy and manage our network as easily
as we wanted to," recalls Robert
Mays, Villanova's director of networking
and communications. As a result, he
says, the university switched from its
traditional equipment supplier to wireless products from Meru Networks. Today, the
university has about 500 thin client,
centrally controlled APs installed, serving
all of its academic buildings and
about one-third of its residence halls.

Technologists and administrators at Washington University in
St. Louis are looking closely at marrying VoIP to WiFi, initially to
benefit the medical school where hospital staff and medical students
need emergency communication capability while on the move. The
university plans to test VoIP features this coming summer.

Much like at Villanova, in the fall of
2005 Fitchburg State College (MA)
mandated that its freshmen use laptops.
In this case, though,
being "caught in the
switch" not only resulted
in providing users
with easy network
access, but the new
wireless network also
came to the aid of the
campus's IT department,
which had been seeking a networking
solution to an ongoing problem at
Fitchburg: Many of the university's
buildings were 75 to 100 years old, so
adding wired connections was proving
not only to be difficult, but even impossible
in some cases.

"We could put, at most, two wired data
ports in many of our classrooms," Charles
Maner, the college's CIO, can now admit.
Wireless was the better option because it
required minimal changes to the antiquated
infrastructure, he explains.

To support its initiative and provide
wireless connectivity, the college selected
RoamAbout 84000 wireless switches
and RoamAbout access points from Enterasys. Currently,
about 150 access points provide
connectivity in classroom buildings, the
campus center, the library, the dining
hall, and other common areas spread
across the college's 31-acre campus.
Battling Bandwidth Hogs
As wireless usage has spread on academic
campuses, bandwidth has become
an issue. That's because as an increasing
number of users rely on these networks,
more bottlenecks can occur. In general,
wireless networks have sufficient bandwidth
to support most data applications,
but recently, as more universities experiment
with video applications (which
usually are bandwidth hogs), they find
themselves chewing up hundreds of
Kbps, or even multiple Mbps, of bandwidth.
So far, video usage has been limited
and the early results promising.

Villanova's faculty, for example, has
begun tinkering with real-time learning
applications (some of which feature video
streaming) without any adverse effects.
And the Creighton University (NE)
wireless network—which relies on Cisco
Systems devices and
has 10,000 users including students, faculty,
and support staff—also has started
to run video transmissions over WiFi.

According to Creighton VP/IT and
CIO Brian Young, "We have a number
of training classes that rely on video
transmissions. Many of our journalism
classes also use various types of video
clips, and faculty video-stream a lot of
movies as part of their presentations."
Young reports that his wireless network
has not had problems handling the highbandwidth
transmissions.
Meanwhile, back at the dorm, video
has taken over on many campuses nationwide:
At some colleges and universities,
classroom capture video is available for
students who missed class, wish to review
recent lectures, or want to pull up
archived lecture material. That's all well
and good, but after class, leisure time is
video time and students' PCs often
replace their TVs. Video applications
such as YouTube are
rapidly gaining popularity, and students
can now download movies or video clips
via a growing number of peer-to-peer
(P2P) applications, or even via schooloffered
services. In some cases, enterprising
students establish legitimate (and
in some cases, illegitimate) businesses
via these applications and can continually
download hundreds of MBs or GBs of
data during the course of a day.

Despite limitations such as QoS (quality of service issues),
and the high cost of VoIP handsets and WiFi cell phones,
the initial results from VoIP/WiFi deployments have been
promising. Emory University has deployed about 150 VoIP
phones on its WiFi network, and technologists report no initial
problems with voice quality.

UPDATE: 802.11n

As 802.11n-compliant products ship, vendors are on Draft 2.0 of the specification and
expect to ratify it by the summer of 2008. Will ratification of this much-needed standard
meet the new deadlines?

THE NEED FOR SPEED is never-ending. As soon as computers add more internal and
external storage, software developers build more complex applications, and networks
need to be able to transmit more and more information. Such is the case with 802.11
wireless LANs, covered previously in this publication (see CT September 2007, "Wireless:
New and Improved!"). In fact, vendors have
embarked on their third significant speed boost, one that promises to deliver at least
100 Mbps (and possibly as much as 600 Mbps) of bandwidth.

This has been a good news/bad news scenario for academic institutions. "It has
been a bit of a challenge to seamlessly integrate lower-speed and higher-speed WiFi
networks," states Brian Young, vice president of IT at Creighton University (NE).

Currently, universities rely on 802.11b, which operates at 11 Mbps, and 802.11g,
which transmits information at a rate of 54 Mbps, to carry their wireless LAN traffic. In
the spring of 2004, the IEEE began working on the 802.11n standard,
which operates at 100 Mbps and offers backward compatibility with both of these networks.
Not only does the new standard support more bandwidth, but it also supplies a
greater transmission range: about double that of 802.11b, according to the IEEE.

Three new features—channel bonding, MIMO (multiple-in-multiple-out), and spatial
multiplexing—helped 802.11n increase its data rate. Normally, an 802.11 radio operates
on a single channel, but channel bonding ties two adjacent channels together to
double the amount of bandwidth available. Typically, wireless LANs supported one
antenna between end points, but MIMO is based on multiple antennas sending and
receiving packets. Spatial multiplexing transmits data packets to different antennas
simultaneously, so that an 802.11n receiver can distinguish between different data
streams. Because these features can double or even triple the amount of data that can
be sent over the airwaves, there has been a lot of interest in the standard.

However, the road from standards committee to shipping products can be long and
winding. Initially, vendors anticipated that the 802.11n work would be finished by the
end of 2006, but that goal proved elusive. Because the work was complicated (and
because many vendors with a wide range of desires and goals were involved), the standards-
making process has dragged on longer than expected. Vendors are now working
on a Draft 2.0 of the specification and expect to ratify it by the summer of 2008. (While
a Draft 3.0 is also on the docket, observers anticipate that it will contain minor rather
than major revisions.)

Even though Draft 2.0 has not been ratified, vendors have begun shipping compliant
products. The Wi-Fi Alliance, an ad hoc vendor consortium that focuses on
compliance testing, reported that close to 100 vendors were shipping such devices at the
end of 2007. The supporters include network equipment vendors such as Cisco Systems, D-Link, Hewlett-Packard, Meru Networks, Netgear, and SMC Networks. In addition, Intel enhanced its Centrino Duo chip to support
802.11n, so Lenovo, Sony, and Toshiba could deliver laptops that can take advantage of the higher speed. Apple has also integrated 802.11n support into its Macintosh line.

As a result, academic institutions are now able to make the most of the additional
bandwidth that the new standard offers. In addition, the 802.11n standard was designed
so that vendors could eventually upgrade to 270 Mbps and 600 Mbps connections—
work that is expected to garner more attention once 802.11n Draft 2.0 is ratified, and
which will continue to usher in new chapters in the never-ending story about higher
transmission speeds.

How are universities and colleges to
stem this growing bandwidth drain?
They can address these new bandwidth
challenges in a couple of ways: First
off, campus technologists can now
boost the speed of the wireless networks—
a new standard
is emerging that
doubles WiFi's top
speed (see "Update:
802.11n").
Another option: ratcheting
up their management
functions.

"In order to prevent
video transmissions from overrunning
our network, we limit the amount of data
students can transmit via P2P applications,"
says Matthew Arthur, director of
network technology services, enterprise
networks at Washington University in
St. Louis. The university has 1,000 Meru
Networks APs supporting 5,500 undergraduates
on its campus and at a few
satellite locations, and expects to double
the number of APs as part of its plan to
make wireless connections available
campuswide in the next 12 to 18 months.

Marrying VoIP to WiFi

In addition to video's growing popularity,
voice over IP (VoIP) has become more
common among higher education institutions.
It has the potential to enable universities
to deliver more sophisticated
voice applications while cutting their
telecommunications costs. With both
WiFi and VoIP gaining momentum, network
managers have been looking at
ways to "marry" the two; the duo thrives
in pockets where mobility and instant
communication are at a premium.

"The first place where we see a need
to run VoIP over WiFi is in our medical
school," says Washington U's Arthur,
adding that the staff and students at the
hospital are often on the move but need
to be contacted quickly in case of an
emergency. The university plans to test
VoIP features this summer.

Still, as academic institutions examine
running VoIP over WiFi, they see a
couple of potential problems. First,
technologists need to look carefully at
the handsets capable of supporting
these transmissions, for this area has
been evolving slowly. IP PBX suppliers
such as 3Com, Avaya, Cisco Systems, and Polycom via its SpectraLink acquisition, have designed wireless
VoIP handsets, but these products tend
to be expensive.

"We talked to Avaya reps about
deploying their VoIP solution, but the
cost was $2,000 per handset," reports
Fitchburg State College's Maner.

One emerging option is WiFi cell
phones that support both WiFi and cellular
transmissions. Convenience is a
major benefit with these devices; after
all, users would prefer to work with one
device rather than a couple. Another plus
is that users can move from outside to
inside, and vice versa, without experiencing
dropped calls. In addition, there
are potential cost savings for universities
and colleges. In certain cases, intra-company
cell phone calls account for 50 percent
or more of an institution's monthly
cellular expenses. But by offloading
those calls to a WiFi network, academic institutions can lower their operating
costs by 10 to 20 percent.

Unfortunately, these WiFi cell
devices are just starting to make their
way to market. And because only a few
of these devices from vendors such as
Motorola, Pantech, and Samsung are shipping, they
too have high price tags at present,
ranging in cost from $400 to $1,000 or
more. Another challenge is that these
handsets tend to drain their batteries
quickly. But keep your eye on the evolution
of these devices as battery life
increases, and costs come down.

Another Problem:
Transmission Difficulties

As academic institutions start to move
beyond data-only transmissions on their
networks, the differences between voice
and data communication become clear.
With the latter, the order in which information
arrives is not important. In fact,
data are broken up into small pieces, sent
in many different directions, and then
recompiled at the receiving site. The
underlying 802.11 infrastructure makes a
best effort to keep it together. While the
network tries to send information in the
proper order, it does not guarantee that is
the case. In fact, in many cases, transmissions
will experience delays and
encounter jitter, so the transmission order
can become a bit jumbled. Normally, it
comes together in the end, and the few
seconds or split seconds of disarray is not
particularly of note to the receiver.

Voice and video applications are not
as forgiving, however. They require a
feature dubbed quality of service (QoS)
where the order is guaranteed, and the
likelihood of delays and jitter are eliminated
or, at the very least, minimized.
If a university runs a wireless network
without QoS, and someone downloads
a large file, that download can overload
the wireless network, lower the quality
of voice calls, and even knock a few
conversations off the airwaves completely.
Understandably then, "QoS is a
major concern for us as we begin to
deploy VoIP on our WiFi networks,"
notes Arthur at Washington University.

Most of us are aware that the IEEE
has been working on this issue since the
turn of the millennium, and ratified the
802.11e standard in 2001. This specification
allows packets to gain bandwidth
priority by defining four classes of traffic
(voice, video, best effort, and background),
each with its own queuing
ability. The idea is that the applications
tell the network how much of a delay
they can tolerate, and then the network
sets aside bandwidth for them accordingly.
Theoretically, when an AP sees a
voice application, it will give those
packets top transmission priority.

Who Sets Network Priorities?

While the 802.11e standard is an
improvement, it has limitations, however.
One problem is that the power to
request different priority levels resides
in client systems. As a result, a user
has the ability to mark an application
such as an e-mail as "high
priority," and have bandwidth set
aside for it. In larger deployments,
though, more control will have to
reside in the IT department in order
for the network policies to be effective.
What's more, although the network
makes a best effort to ensure
network bandwidth is available, it
stops short of guaranteeing that it
can deliver that bandwidth.

Despite those limitations, the initial
results from VoIP/WiFi deployments
have been promising. Emory University
has deployed about 150 VoIP phones on
its WiFi network. "We are still in an
early stage of rolling
out and testing VoIP,"
says Brooks at that
institution, "but at
least initially, there
have not been any
problems with the
voice quality."

WiFi usage is now
expanding across college
campuses as many colleges and
universities move to provide their campuses
with 100 percent wireless network
availability. Clearly, as academic
institutions put the finishing touches on
wireless network rollouts, they are looking
for ways to expand their usage of
these networks. And where video transmissions
are making their way onto
these networks, voice communications
are soon to follow, say the pundits.
Wireless is quickly becoming a common
rather than a niche technology.

Maner at Fitchburg State puts it succinctly:
"For us, there has been a significant
increase in how often our users
work with wireless connections, and
that has led to a lot less stress on our
wired networks."

Paul Korzeniowski is a Massachusetts-based freelance writer specializing in networking issues. His reporting has appeared in Business 2.0, Entrepreneur, Investors Business Daily, Newsweek, and InformationWeek.